Conventionally, autopilot techniques to keep a specified course are known. JP2013-079813A discloses a configuration in which autopilot is performed for a ship.
The display device of JP2013-079813A (a touch panel device), upon a predetermined operation thereon to specify a course, outputs the course to an autopilot device. The autopilot device controls a rudder to keep an azimuth of the specified course. Since the display device is connected with a fish finder, it can also display an underwater detection image which is a detection result of the fish finder. The display device, upon a predetermined operation thereon to specify a school of fish in the underwater detection image, instructs the autopilot device to control the ship to travel toward a position where the specified school of fish exists.
Meanwhile, the display device such as the one in JP2013-079813A is fixed to a position in a location where the ship is steered (e.g., the bridge, the command room of the ship). Therefore, the user needs to stay in front of the display device all the time, otherwise he/she cannot specify a course for the autopilot. Since the user may take a break, go fishing, etc., at a different location, he/she needs to move to the front of the display device to change the course for the autopilot every time. Therefore, it is inconvenient for the user and it is also difficult to specify the course quickly.
Moreover, the user generally confirms the situation in the vicinity of the ship concerned visually in addition to by using a detection device, such as a radar apparatus. The user may specify the course for the autopilot based on the visually confirmed information. In such a case, in order to specify the course by using the display device, the correspondence between an actual azimuth and an azimuth on the display device needs to be grasped, and it is difficult to smoothly specify a desired course.
Note that, not only when specifying the course for the autopilot, but also when turning the ship to a desired azimuth (the course is not kept after the ship is turned), similar issues arise.